Conventionally, as an article conveyance device that can convey an article and can arbitrarily change a conveyance direction on a conveyance line of the article, a various types of devices are known.
For example, as Patent Literature 1, there is a type of article conveyance device in which a large number of electrostatic actuators are disposed in a lattice shape on a conveyance surface of an article. In this device, the article is moved on a carrier, by providing a large number of square-shaped stators on the conveyance surface, and suspending the carrier therein via a spring member in advance, and by operating an attraction electrode provided at a bottom surface and a lateral face within the stator and thereby controlling operation of the carrier.
Also, Patent Literature 2 discloses a technique, in which a large number of small rollers are disposed on the conveyance surface of an article such that a rotation axis becomes parallel to the conveyance surface, and the rotation and direction of the rollers are controlled, thereby the conveyance direction of the article to be loaded on the rollers is controlled.
Also, Patent Literature 3 discloses a technique of controlling the conveyance direction of an article by alternately disposing rollers having rotation axes orthogonal to each other on the conveyance surface and by controlling the rotation of the rollers.
The article conveyance devices according to the conventional technologies of the Patent Literatures 1 to 3 are configured from a large number of equipments such as the electrostatic actuator and the small roller, and need to drive the equipments simultaneously, thereby the configuration becomes complex and a control scheme become also complex. Therefore, manufacturing costs and maintenance expenses become higher, and furthermore problems with the equipment are also easily caused. Also, in such configurations, since concavities and convexities are caused at the conveyance surface with which the article comes into contact, it becomes difficult to convey the article as the article becomes smaller with respect to the concavities and convexities. Thus, it is difficult to enable conveyance of articles having varying sizes from small to large by using a single article conveyance device.
As a device in which such problems do not happen, there is also suggested an article conveyance device that conveys the article by imparting vibration to the movable bench having the conveyance surface for loading the article.
For example, Patent Literature 4 discloses a technique of differing the conveyance direction by imparting vibrations having the same frequency in the vertical and horizontal directions with respect to a movable body (movable bench) that has a trajectory for the article conveyance to cause elliptical vibrations, and by setting a phase difference of the vibrations in each direction in accordance with the coefficient of friction. In this article conveyance device, since the conveyance surface on the movable bench can be configured as a plane, articles with a wide variety of shapes and sizes can be conveyed. Also, this article conveyance device has many advantages in terms of downsizing and the manufacturing cost, because both of a vibration device that is a mechanical device part, and a control system for controlling the vibration of this vibration device can be easily configured.
In addition, this article conveyance device can also be used as an article sorting device for sorting a plurality of types of articles having different coefficients of friction by differing only the control system, because the article conveyance device can control the conveyance direction in accordance with the coefficient of friction of the article. Similarly to the article conveyance device, this case also has many advantages in terms of the downsizing and the manufacturing cost because the simple configuration can be provided.
In the present invention, the above-described article conveyance device and article sorting device are referred together to as an article moving device which includes a device having a function of either conveying or sorting an article or a device having both functions. Also, in the present specification, a mechanical device part capable of being used commonly to these devices is referred to as a vibration device.